3.2-stable review patch. If anyone has any objections, please let me know.
------------------ From: Sasha Levin <[email protected]> [ Upstream commit bcf1b70ac6eb0ed8286c66e6bf37cb747cbaa04c ] A phonet packet is limited to USHRT_MAX bytes, this is never checked during tx which means that the user can specify any size he wishes, and the kernel will attempt to allocate that size. In the good case, it'll lead to the following warning, but it may also cause the kernel to kick in the OOM and kill a random task on the server. [ 8921.744094] WARNING: at mm/page_alloc.c:2255 __alloc_pages_slowpath+0x65/0x730() [ 8921.749770] Pid: 5081, comm: trinity Tainted: G W 3.4.0-rc1-next-20120402-sasha #46 [ 8921.756672] Call Trace: [ 8921.758185] [<ffffffff810b2ba7>] warn_slowpath_common+0x87/0xb0 [ 8921.762868] [<ffffffff810b2be5>] warn_slowpath_null+0x15/0x20 [ 8921.765399] [<ffffffff8117eae5>] __alloc_pages_slowpath+0x65/0x730 [ 8921.769226] [<ffffffff81179c8a>] ? zone_watermark_ok+0x1a/0x20 [ 8921.771686] [<ffffffff8117d045>] ? get_page_from_freelist+0x625/0x660 [ 8921.773919] [<ffffffff8117f3a8>] __alloc_pages_nodemask+0x1f8/0x240 [ 8921.776248] [<ffffffff811c03e0>] kmalloc_large_node+0x70/0xc0 [ 8921.778294] [<ffffffff811c4bd4>] __kmalloc_node_track_caller+0x34/0x1c0 [ 8921.780847] [<ffffffff821b0e3c>] ? sock_alloc_send_pskb+0xbc/0x260 [ 8921.783179] [<ffffffff821b3c65>] __alloc_skb+0x75/0x170 [ 8921.784971] [<ffffffff821b0e3c>] sock_alloc_send_pskb+0xbc/0x260 [ 8921.787111] [<ffffffff821b002e>] ? release_sock+0x7e/0x90 [ 8921.788973] [<ffffffff821b0ff0>] sock_alloc_send_skb+0x10/0x20 [ 8921.791052] [<ffffffff824cfc20>] pep_sendmsg+0x60/0x380 [ 8921.792931] [<ffffffff824cb4a6>] ? pn_socket_bind+0x156/0x180 [ 8921.794917] [<ffffffff824cb50f>] ? pn_socket_autobind+0x3f/0x90 [ 8921.797053] [<ffffffff824cb63f>] pn_socket_sendmsg+0x4f/0x70 [ 8921.798992] [<ffffffff821ab8e7>] sock_aio_write+0x187/0x1b0 [ 8921.801395] [<ffffffff810e325e>] ? sub_preempt_count+0xae/0xf0 [ 8921.803501] [<ffffffff8111842c>] ? __lock_acquire+0x42c/0x4b0 [ 8921.805505] [<ffffffff821ab760>] ? __sock_recv_ts_and_drops+0x140/0x140 [ 8921.807860] [<ffffffff811e07cc>] do_sync_readv_writev+0xbc/0x110 [ 8921.809986] [<ffffffff811958e7>] ? might_fault+0x97/0xa0 [ 8921.811998] [<ffffffff817bd99e>] ? security_file_permission+0x1e/0x90 [ 8921.814595] [<ffffffff811e17e2>] do_readv_writev+0xe2/0x1e0 [ 8921.816702] [<ffffffff810b8dac>] ? do_setitimer+0x1ac/0x200 [ 8921.818819] [<ffffffff810e2ec1>] ? get_parent_ip+0x11/0x50 [ 8921.820863] [<ffffffff810e325e>] ? sub_preempt_count+0xae/0xf0 [ 8921.823318] [<ffffffff811e1926>] vfs_writev+0x46/0x60 [ 8921.825219] [<ffffffff811e1a3f>] sys_writev+0x4f/0xb0 [ 8921.827127] [<ffffffff82658039>] system_call_fastpath+0x16/0x1b [ 8921.829384] ---[ end trace dffe390f30db9eb7 ]--- Signed-off-by: Sasha Levin <[email protected]> Acked-by: Rémi Denis-Courmont <[email protected]> Signed-off-by: David S. Miller <[email protected]> Signed-off-by: Ben Hutchings <[email protected]> --- net/phonet/pep.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/net/phonet/pep.c b/net/phonet/pep.c index 2ba6e9f..007546d 100644 --- a/net/phonet/pep.c +++ b/net/phonet/pep.c @@ -1046,6 +1046,9 @@ static int pep_sendmsg(struct kiocb *iocb, struct sock *sk, int flags = msg->msg_flags; int err, done; + if (len > USHRT_MAX) + return -EMSGSIZE; + if ((msg->msg_flags & ~(MSG_DONTWAIT|MSG_EOR|MSG_NOSIGNAL| MSG_CMSG_COMPAT)) || !(msg->msg_flags & MSG_EOR)) -- 1.7.10 -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
